Molecular function of Klotho protein on vascular walls and trying to identify unknown factors protecting against endothelial dysfunction

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In this study, we found that Klotho protein proliferated the cGMP production by ANP in cultured vascular endothelial cells and also proliferated the cGMP production by CNP in cultured vascular smooth muscle cells. The proliferation by Klotho protein was inhibited by GF 109203X, a PKC inhibitor. Klotho protein also accelerated Ang II - induced proliferation of vascular smooth muscle cells. Specific inhibitors of protein kinases A and C (PKA, PKC) inhibited the acceleration by Klotho protein. Moreover, we showed that Klotho protein increases ec-cNOS protein expression, but dose not increase ec-cNOS gene expression in cultured vascular endothelial cells. We generated transgenic lines of rats that over-express klotho under the control of the human elongation factor. No significant difference was observed in nitric oxide metabolites in urine between the transgenic rats and wild-type rats.On the other hand, we tried to identify the unknown factors protecting against endothelial dysfunction, that express in renal tubules in the kidney. Kidneys were collected both from the rats suffering from balloon-mediated aortic injury and from controlled rats. Renal cortex was collected from the kidneys. Total RNA was extracted by the acid guanidium thiocyanate-phenol-chloroform method. To obtain gene expression profile of the renal cortex prepared form the rats suffering from balloon-mediated aortic injury, a microarray analysis was performed. No significant difference was observed in gene expression profile between the rats suffering from balloon-mediated aortic injury and the controlled rats.